Most residential buildings, hotels, office buildings, and the like, in the industrialized areas of the world, are serviced by water and/or natural gas, oil or propane. These services involve pipes, valves, and other mechanized devices for conveying the liquids and/or gases and require periodic maintenance. Not infrequently, there is a malfunction and undesirable water or gas leaks into the building, thereby causing costly unwanted damage and creating a safety hazard. In buildings which are heated, there is a constant danger that lethal carbon monoxide will be generated from improper combustion of the fuel source. Insurance companies insuring buildings or occupants which are affected by unwanted water or gas leaks annually pay out large compensation for such unwanted water or gas damage.
There is a strong need for an automatic locally or remotely operated system which can be installed in single or multiple residential buildings or commercial buildings and can automatically detect undesirable water or gas leakage, and automatically shut off the source of such unwanted liquid or gas leakage, until the source of the leakage can be repaired. Insurance rates would be reduced if the risk of potential damage was minimized. Building owners would be more comfortable with the reduced risk of accidental liquid or gas damage, and in the case of leaking or noxious gases, alerted as to their safety.
The following patents disclose apparatus or systems which may be pertinent to the subject matter of this application.
______________________________________ U.S. Pat. No. Owner ______________________________________ 3,757,317 U.S. Dynasty Corp. 4,024,887 Vought Corp. 4,134,022 Honeywell U.S.A. 4,248,087 Haliburton Company 4,437,497 Enander 4,715,398 Co Be La B's Inc. 4,736,763 Britton 5,240,022 Franklin ______________________________________
U.S. Pat. No. 4,134,022, Honeywell, U.S.A., discloses a liquid level sensing apparatus that has a source for supplying a signal of a predetermined frequency. A level sensor is connected to the source and has an output for signalling an output signal which has the predetermined frequency, so long as the level of the material being sensed is not at a predetermined level. The apparatus includes a frequency sensitive circuit for receiving the output signal from the level sensor and for providing an output whenever the frequency of the signal is above or below the predetermined frequency. A load which is responsive to the output from the frequency sensitive circuit is connected to the circuit. This patent does not disclose an integrated local or remotely operated system for detecting liquid and gas leaks and automatically shutting off the source of the liquid or gas leak.
U.S. Pat. No. 5,240,022, Franklin, discloses an automatic shut-off valve system for installation, for instance, in the water supply line to a hot water heater and includes a sensor to detect leakage electrically by sensing moisture, and then shutting off the supply line in response. The valve mechanism includes a spring loaded ball valve normally latched in the open position which is unlatched and hence closes by the contraction of a BioMetal (trade-mark) wire which activates a torsion spring to rotate the ball valve. The valve is controlled by a microprocessor which includes self test features, and the valve system may operate for a year or more on battery power. This patent does not disclose gas sensors or application of the system to multiple unit buildings or networked systems.